Whereas I use a TLR, so the R72 filter stays on the taking lens while I compose using the separate viewing lens. I'd use the same approach with a rangefinder camera.
One caution though - the spectral sensitivity of different meters varies. So if two photographers are metering through their filters, even if the light is the same, the meter readings may differ.
As a result, each photographer needs to experiment with their meter and their filter, their work-flow, their experience with lighting conditions and their particular aesthetic preferences to determine what will work best for them.
Oh, and bracket.